17-63968201-C-G

Variant names:

• chr17-63968201-C-G
• rs560230431
• NM_000334.4:c.858G>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_000334.4(SCN4A):​c.858G>C​(p.Pro286Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. P286P) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: SCN4A NM_000334.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.864
• Publications: 0 publications found

Genes affected

SCN4A (HGNC:10591): (sodium voltage-gated channel alpha subunit 4) Voltage-gated sodium channels are transmembrane glycoprotein complexes composed of a large alpha subunit with 24 transmembrane domains and one or more regulatory beta subunits. They are responsible for the generation and propagation of action potentials in neurons and muscle. This gene encodes one member of the sodium channel alpha subunit gene family. It is expressed in skeletal muscle, and mutations in this gene have been linked to several myotonia and periodic paralysis disorders. [provided by RefSeq, Jul 2008]

SCN4A Gene-Disease associations (from GenCC):

• hyperkalemic periodic paralysis

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• paramyotonia congenita of Von Eulenburg

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), G2P, Orphanet
• SCN4A-related myopathy, autosomal recessive

  Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina, ClinGen
• hypokalemic periodic paralysis, type 2

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• potassium-aggravated myotonia

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• congenital myasthenic syndrome 16

  Inheritance: AR Classification: STRONG, LIMITED Submitted by: PanelApp Australia, Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• congenital myopathy

  Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
• congenital myopathy 22A, classic

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• acetazolamide-responsive myotonia

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hypokalemic periodic paralysis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• myotonia fluctuans

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• myotonia permanens

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• postsynaptic congenital myasthenic syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.69).
• BP7: Synonymous conserved (PhyloP=0.864 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SCN4A	NM_000334.4	c.858G>C	p.Pro286Pro	synonymous_variant	Exon 6 of 24	ENST00000435607.3	NP_000325.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SCN4A	ENST00000435607.3	c.858G>C	p.Pro286Pro	synonymous_variant	Exon 6 of 24	1	NM_000334.4	ENSP00000396320.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.69
CADD	Benign	5.6
DANN	Benign	0.65
PhyloP100		0.86

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs560230431; hg19: chr17-62045561;